Verify the Ampere’s law for magnetic field of a point dipole of dipole moment . Take C as the closed curve running clockwise along (i) the z-axis from z = a > 0 to z = R; (ii) along the quarter circle of radius R and center at the origin, in the first quadrant of x-z plane; (iii) along the x-axis from x = R to x = a, and (iv) along the quarter circle of radius an and center at the origin in the first quadrant of x-z plane.
Magnetic field induction at a point at distance r from the magnetic dipole is
i) Along z-axis from P to Q
… (1)
ii) Along the quarter circle QS of radius R is given in the figure below
… (2)
iii) Along x-axis over path ST
.... (3)
Since angle between (-M) and dl is 90 degrees.
iv) Along the quarter circle TP of radius a.
= …(4)